Here are my two cents worth. Being a long term buddhist, and knowing that Leonard has been a rather serious and intense Buddhist practitioner/student/retreater/monk his whole life I tend to look for Buddhist-related themes in his songs and find many.

"A brief elaboration of a tube"

The key for me to understanding this expression is not the word tube but the word brief. I had also contemplated the TV analogy of a tube and this is possible but I think another interpretation makes more sense. In Buddhism there is a belief in reincarnation (Please remember that Leonard is and has been a BIG-TIME Buddhist for over 30 years and this is basic Buddhist theory); each life has had a series of previous lives and will have a series of future lives (until enlightenment, which is when the tube stops). The tube I see as a visual metaphor for this Buddhist truth. Leonard Cohen's very subtle mind had past incarnations (the previous sections of the tube) and will have another incarnation (assuming he does not become/is not now enlightened). These are all sections of the tube. We would usually imagine a tube that is one color and one material (plumbing tubing for example); for this analogy one could possibly imagine a tube that changes both color and material as it progresses (different bodies,beings etc). That kind of tube would still be a tube. I think Leonard's point is that he is an impermanent phenomenon/appearance in the world, and also that he has had previous lives and may have future lives if he does not become enlightened.

I may be wrong, only Leonard knows, and the few people to whom he may have passed his actual lyrical intentions.

He is a powerful poet and a holy man. I call him "Lama Leonard"

Sean

If you become the ocean you will not become seasick....Jikan (aka Leonard Cohen)

It's comin' from the feel that this ain't exactly real, or it's real, but it ain't exactly there! . Jikan

He will speak these words of wisdom
Like a sage, a man of vision
Though he knows he’s really nothing
But the brief elaboration of a tube

At some point during some internet research I was doing quite a while back now I stumbled upon what I felt to be a more specific and consistent seeming answer to this "tube" conundrum.

As most here know, Leonard considered a lot of different viewpoints on things, and while he may have moved on in many cases, still he may have kept with him certain ideas along the way. One such idea has to do with -- and I believe this comes from Scientology -- but there is the idea of the human race as being concocted in a test tube in a laboratory, as it were -- as some manner of genetic engineering; this by extraterrestrial beings.

If anyone here has some expertise in this -- or a desire to research Scientology (something I'm lacking at present) -- you can probably trace what I'm saying here back to its source.

On the topic of Scientology, Leonard has always said he was "impressed by their data," and so on that basis I believe what I've brought up here is something to consider seeing how "a brief elaboration of a tube" so effortlessly fits in with such an interpretation.

Violet wrote:He will speak these words of wisdom
Like a sage, a man of vision
Though he knows he’s really nothing
But the brief elaboration of a tube

At some point during some internet research I was doing quite a while back now I stumbled upon what I felt to be a more specific and consistent seeming answer to this "tube" conundrum.

As most here know, Leonard considered a lot of different viewpoints on things, and while he may have moved on in many cases, still he may have kept with him certain ideas along the way. One such idea has to do with -- and I believe this comes from Scientology -- but there is the idea of the human race as being concocted in a test tube in a laboratory, as it were -- as some manner of genetic engineering; this by extraterrestrial beings.

If anyone here has some expertise in this -- or a desire to research Scientology (something I'm lacking at present) -- you can probably trace what I'm saying here back to its source.

On the topic of Scientology, Leonard has always said he was "impressed by their data," and so on that basis I believe what I've brought up here is something to consider seeing how "a brief elaboration of a tube" so effortlessly fits in with such an interpretation.

Violet, I have done too some Internet research. I have come upon with this:

There is a reoccurring metaphor that occurs in his work of uniting with the highest and the lowest. In “Beautiful Losers” he describes this concept in a parable of the radio. He needs to reach up and become the aerial while also reaching down to become the ground, only through extending in both these ways can he reduce the static and hear the gospel music sing out, the sound of the ordinary eternal machinery (It is no surprise that this metaphor is revisited in his latest album, released a month before his death). It doesn’t take much tweaking of the language to see he is talking about what a Thelemite would call Knowledge and Conversation with the Holy Guardian Angel. Indeed, Cohen’s description of this phenomena was my introduction to the concept. He provided the why. Crowley provided the how. His “Book of Mercy” is my go-to recommendation when someone asks me about a record of K&C. Like most of his books, I have bought it so many times because I can’t help but give it away to anyone I think can benefit from it. Although, Cohen does not use Thelemic jargon, his works are undeniable compatible. He is a Teacher in full command of the symbols of the soul. From my view, his conversations in “Book of Mercy” cumulate in the song “Going Home”, which stands as the starkest and precise description of the HGA [Holy Guardian Angel] experience that I have ever encountered:

“I love to speak with Leonard
He’s a sportsman and a shepherd
He’s a lazy bastard
Living in a suit
But he does say what I tell him
Even though it isn’t welcome
He just doesn’t have the freedom
To refuse
He will speak these words of wisdom
Like a sage, a man of visionThough he knows he’s really nothing
But the brief elaboration of a tube
…..
He wants to write a love song
An anthem of forgiving
A manual for living with defeat
A cry above the suffering
A sacrifice recovering
But that isn’t what I need him
To complete
I want him to be certain
That he doesn’t have a burden
That he doesn’t need a vision
That he only has permission
To do my instant bidding
Which is to say what I have told him
To repeat.”

Where have I heard the “tube” metaphor to describe the HGA [Holy Guardian Angel] before? Hmm. Somebody bearded, I think."

Thelema is a philosophy of life based on the maxims "do your will: it will be the whole law", and "love is the law, love under will." The ideal of "do your will" and its association with the word thelema has its antecedent in François Rabelais (1494-1553), but was more developed and popularized by Aleister Crowley (1875-1947), who founded a religion called thelema, based In this ideal. The word itself is the English transliteration of the Greek noun koiné θέλημα (/ θəˈliːmə /): 'will', which comes from the verb θέλω (/ θəˈlo /): to want, to desire, purpose. Some writings of early Christianity use this word to refer to the will of the god Yahweh, the human will.

Here is some information regarding the Thelemite:

"Thelema (/θəˈliːmə/) is a religion based on a philosophical law of the same name, adopted as a central tenet by some religious organizations. The law of Thelema is "Do what thou wilt shall be the whole of the Law. Love is the law, love under will." The law of Thelema was developed in the early 1900s by Aleister Crowley, an English writer and ceremonial magician. The word thelema is the English transliteration of the Koine Greek noun θέλημα (pronounced Greek: [θélima]) "will", from the verb θέλω (/ θəˈlo /): "to will, wish, want or purpose."

The word θέλημα (thelema) is rare in classical Greek, where it "signifies the appetitive will: desire, sometimes even sexual", but it is frequent in the Septuagint. Early Christian writings occasionally use the word to refer to the human will, and even the will of God's opponent, the Devil, but it usually refers to the will of God. One well-known example is in the "Lord's Prayer" (Matthew 6:10), “Thy kingdom come. Thy will (Θελημα) be done, On earth as it is in heaven.” It is used later in the same gospel (26:42), "He went away again a second time and prayed, saying, "My Father, if this cannot pass away unless I drink it, Thy will be done." In his 5th-century Sermon on 1 John 4:4–12, Augustine of Hippo gave a similar instruction: "Love, and what thou wilt, do." (Dilige et quod vis fac).

In the Renaissance, a character named "Thelemia" represents will or desire in the Hypnerotomachia Poliphili of the Dominican monk Francesco Colonna. The protagonist Poliphilo has two allegorical guides, Logistica (reason) and Thelemia (will or desire). When forced to choose, he chooses fulfillment of his sexual will over logic. Colonna's work was a great influence on the Franciscan monk François Rabelais, who in the 16th century, used Thélème, the French form of the word, as the name of a fictional abbey in his novels, Gargantua and Pantagruel. The only rule of this Abbey was "fay çe que vouldras" ("Fais ce que tu veux", or, "Do what thou wilt"). In the mid-18th century, Sir Francis Dashwood inscribed the adage on a doorway of his abbey at Medmenham, where it served as the motto of the Hellfire Club. Rabelais's Abbey of Thelema has been referred to by later writers Sir Walter Besant and James Rice, in their novel The Monks of Thelema (1878), and C. R. Ashbee in his utopian romance The Building of Thelema (1910).

The law of Thelema was developed in the early 1900s by Aleister Crowley, an English writer and ceremonial magician. He believed himself to be the prophet of a new age, the Æon of Horus, based upon a spiritual experience that he and his wife, Rose Edith, had in Egypt in 1904. By his account, a possibly non-corporeal or "praeterhuman" being that called itself Aiwass contacted him and dictated a text known as The Book of the Law or Liber AL vel Legis, which outlined the principles of Thelema. An adherent of Thelema is a Thelemite.

The words are not his, he is just the speaking tube passing them on...

"But he does say what I tell him
Even though it isn’t welcome
He will never have the freedom
To refuse

He will speak these words of wisdom
Like a sage, a man of vision
Though he knows he’s really nothing
But the brief elaboration of a (speaking) tube"

The 'brief' could suggest his mortality, I guess.

My first interpretation on hearing "Going Home" was also to identify the "tube" with a speaking tube, a nineteenth- century mechanical intercom device typically used in upper-class houses for the owners and family to communicate with their servants. Thus, I read "a brief elaboration on a tube" as indicating that LC was but a slightly more complicated version of one of these physical tubes used to transmit orders to the staff.

Does anyone know how old LC's family home in the Montreal area is and if it has (or might have once had) a system of speaking tubes?

In the temple (?) the deity's answers to questions about life etc get interpreted.

So when I heard the lyric, I thought it was about living out one's karma etc - the 'leonard' in the song is speaking like a sage but really just acting out what was laid out for him in god's tube, 'to say what I have told him to repeat'.